Practitioners of ninjutsu, "the skill of going unperceived" or "the art of stealth".
Since Bushidō, the samurai code, forbade certain valuable measures as dishonorable, a Daimyo could not expect his own troops to perform the tasks required; thus, he had to buy or broker the assistance of ninja to perform selective strikes, espionage, assassination, and infiltration of enemy strongholds.
Ninja employed a variety of weapons and tricks using gunpowder. Smoke bombs and firecrackers were widely used to aid an escape or create a diversion for an attack. They used timed fuses to delay explosions. Ōzutsu (cannons) they constructed could be used to launch fiery sparks as well as projectiles at a target. Small "bombs" called metsubushi ("eye closers") were filled with sand and sometimes metal dust. This sand would be carried in bamboo segments or in hollowed eggs and thrown at someone, the shell would crack, and the assailant would be blinded. Even land mines were constructed to use a mechanical fuse or a lit, oil-soaked string. Secrets of making desirable mixes of gunpowder were strictly guarded in many ninja clans.
Other forms of trickery were said to be used for escaping and combat. Ashiaro are wooden pads attached to the ninja's tabi (thick socks with a separate "toe" for bigger toe; used with sandals). The ashiaro would be carved to look like an animal's paw, or a child's foot, allowing the ninja to leave tracks that most likely would not be noticed.
A small ring worn on a ninja's finger called a Shobo would be used for hand-to-hand combat. The shobo would have a small notch of wood used to hit assailant's pressure points for sharp pain, sometimes causing temporary paralysis. A suntetsu is very similar to a shobo. It could be a small oval shaped piece of wood affixed to the finger by a small strap. The suntetsu would be held against a finger on the palm-side and when the hand was thrust at an opponent using the longer piece of wood to target pressure points such as the solar plexus.
The shikoro ken (saw sword) was said to be used to gain entry into buildings, and could also have a double use by cutting (or slashing in this case) opponents.
The Shuriken is a weapon that was barely ever used for throwing. It would be stuck into a wall or the ground to be used as a distraction, similar to Caltrops. Shuriken were often used coated with poison so when in direct combat with another the ninja could throw the shuriken and have a more substantial effect than the minor physical injury (with potentially severe effects depending on the strength of the poison). Shuriken does not actually refer to a singular weapon, in actuality the word refers to the general group of a ninja's throwing weapons ie; shaken and kunai and various sharpened conical or spike-shaped pieces of metal.
Many ninja disguised themselves as farmers so their weapons (the Kama, for example) could double as both weapons and farming implements.
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